Republican Scott Brown's victory Tuesday in a Senate special election in Massachusetts blindsided President Obama and Democratic leaders, who had nearly reached the finish line on an ambitious overhaul of the nation's health-care system and were beginning to turn their attention to other challenges, namely creating jobs and lowering the deficit.

The loss of their Senate supermajority has required a frantic reassessment of their strategy. Pelosi (D-Calif.) and Senate Majority Leader Harry M. Reid (D-Nev.) have pledged to complete work on the massive bill they started nearly a year ago, but they have yet to identify a clear way forward that will appeal broadly to their rank-and-file.

Obama added to the confusion Wednesday when he seemed to endorse one option: having both the House and the Senate start from scratch, by voting on a scaled-back package of popular provisions that would crack down on insurance companies but provide health coverage to far fewer additional people.

"We know that we need insurance reform, that the health insurance companies are taking advantage of people," Obama told ABC News in an interview. "We know that we have to have some form of cost containment because, if we don't, then our budgets are going to blow up. And we know that small businesses are going to need help."

That message alarmed House Democratic leaders who had been seeking to round up votes for the Senate bill -- Obama's first choice, they had believed. The White House quickly moved to clarify that the president still wants comprehensive reform.

"Right now there are a lot of discussions going on about the best path forward," spokesman Reid Cherlin said in a statement. "But let's be clear that the president's preference is to pass a bill that meets the principles he laid out months ago: more stability and security for those who have insurance, affordable coverage options for those who don't, and lower costs for families, businesses, and governments."

Pelosi spent the day huddled in her Capitol office with various Democratic factions. Senior aides said she has yet to identify the 218 votes needed to push the Senate bill through her chamber, nor is she convinced that the bill is politically sound.

But she reiterated her resolve to send a health-care bill to Obama's desk. "We heard the people, and hopefully we will move forward with their considerations in mind. But we will move forward in the process," Pelosi told the U.S. Conference of Mayors in a speech.

Reid, meanwhile, struck a more cautious note. "We're not going to rush into anything," he told reporters after a Senate Democratic lunch. "Remember, the bill we passed in the Senate is good for a year. There are many different things that we can do to move forward on health care, but we're not making any of those decisions now."

Caution from moderates

Moderate members of Reid's caucus also urged restraint, interpreting the Massachusetts outcome as a clear signal against advancing such a huge bill along party lines.

"I felt from the beginning that the best way to adopt anything as major as health-care reform was to do it in a bipartisan way," said Sen. Joseph I. Lieberman (I-Conn.). "You've got to listen to the message from Massachusetts, and I think it was all about, they want us to work together, they don't want us to do too much at once, and they want to feel that we're listening to them."